Rock Island and Silvis both had problems with broken water mains on Thursday.
Six water main breaks in Rock Island left five water towers nearly empty, dropping water pressure for many residents east of 11th Street and south of 7th Avenue, city officials said.
Repairs already were having an effect by late Thursday morning, with water pressure beginning to return to normal and water towers refilling, city public works director Bob Hawes said.
The most significant breakwas in an alley behind the 1500 block of 36th Street, he said. One of the five towers was within a block of that break, he said, and likely would take longer to refill.
The cause of the breaks were unknown, although Mr. Hawes said winter water main problems are common. Of the 80 or 100 breaks the city deals with each year, most happen in the winter.
Silvis reported two water main breaks Thursday, one at 1130 12th St. and one at 261 5th St.
A boil order was issued for the area around the 5th Street break, which was reported Wednesday, with door tags informing residents. New door tags will be applied with the boil order is lifted.
Silvis officials said a boil order likely would not be needed for the area around the 12th Street break. If a boil order is needed, tags will be placed on the doors of affected properties if a boil order is issued for the area.
Moline's website on Thursday noted one boil order in the 7200 block of 37th Avenue late Thursday.
Across the river, Lisa Reisen of Iowa American Water said there has been only one significant break in the last week -- at River Drive and Warren Street in Davenport.
"That break has been repaired, and currently street repair and restoration in underway," she said.
Customers in the 900 and 1000 blocks of West River Drive were under a precautionary boil advisory until 9 p.m. Thursday.